A student is given the atomic mass of 816O (which includes the masses of 8 orbital electrons) and wishes to compute the nucleus’s mass defect. Which statement describes the correct preliminary step?
a) Use the given atomic mass directly; the electron masses will ultimately cancel in the binding-energy formula.
b) Subtract only one electron mass from the atomic mass before using it, because the atom is overall neutral.
c) Subtract the mass of all 8 electrons from the atomic mass before inserting it in the mass-defect calculation.
d) Add the mass of 8 electrons to the atomic mass before inserting it in the mass-defect calculation.